Run-of-river type hydroelectrical power plants are the facilities that use only the available flow on the river without storing it to generate electrical energy. These kind of facilities are composed of structural components such as diversion weir, conveyance line, forebay, penstock and power house. In this thesis, a computer program called &ldquo / MiniHEPP Hydraulic Design&rdquo / is developed in order to perform the hydraulic design of run-of-river type hydropower plants. This program which runs under the Windows operating system, was developed in C# programming language. MiniHEPP Hydraulic Design is capable of performing hydraulic design of structural components of diversion weir with sidewise intake and overflow spillway, canal, forebay, and penstock. In addition, it can determine the optimum design discharge and penstock diameter of this type of hydropower plants.

In this study / gas production by depressurization method from a hydrate reservoir containing free gas zone below the hydrate zone is numerically modeled through 3 dimensional, 3 phase, non-isothermal reservoir simulation. The endothermic nature of hydrate decomposition requires modeling to be non-isothermal / hence energy balance equations must be employed in the simulation process. TOUGH-Fx, the successor of the well known multipurpose reservoir simulator TOUGH2 (Pruess [24]) and its very first module TOUGH-Fx/Hydrate, both developed by Moridis et.al [23] at LBNL, are utilized to model production from a theoretical hydrate reservoir, which is first studied by Holder [11] and then by Moridis [22], for comparison purposes. The study involves 2 different reservoir models, one with 30% gas in the hydrate zone (case 1) and other one with 30% water in the hydrate zone (case 2). These models are further investigated for the effect of well-bore heating. The prominent results of the modeling study are: &amp / #8226 / In case 1, second dissociation front develops at the top of hydrate zone and most substantial methane release from the hydrate occurs there. &amp / #8226 / In case 2 (hydrate-water in the hydrate zone), because a second dissociation front at the top of hydrate zone could not fully develop due to high capillary pressure acting on liquid phase, a structure similar to ice lens formation is observed. &amp / #8226 / Initial cumulative replenishment (first 5 years) and the replenishment rate (first 3.5 years) are higher for case 2 because, production pressure drop is felt all over the reservoir due to low compressibility of water and more hydrate is decomposed. Compared to previous works of Holder [11] and Moridis [22], amount of released gas contribution within the first 3 years of production is significantly low which is primarily attributed to the specified high capillary pressure function.

In the first part of this study, two entropy methods under different distribution assumptions are examined on a network of stream gauging stations located in Kizilirmak Basin to rank the stations according to their level of importance. The stations are ranked by using two different entropy methods under different distributions. Thus, showing the effect of the distribution type on both entropy methods is aimed. In the second part of this study, autoregressive models with asymmetric innovations and an artificial neural network model are introduced. Autoregressive models (AR) which have been developed in hydrology are based on several assumptions. The normality assumption for the innovations of AR models is investigated in this study. The main reason of making this assumption in the autoregressive models established is the difficulties faced in finding the model parameters under the distributions other than the normal distributions. From this point of view, introduction of the modified maximum likelihood procedure developed by Tiku et. al. (1996) in estimation of the autoregressive model parameters having non-normally distributed residual series, in the area of hydrology has been aimed. It is also important to consider how the autoregressive model parameters having skewed distributions could be estimated. Besides these autoregressive models, the artificial neural network (ANN) model was also constructed for annual and monthly hydrologic time series due to its advantages such as no statistical distribution and no linearity assumptions. The models considered are applied to annual and monthly streamflow data obtained from five streamflow gauging stations in Kizilirmak Basin. It is shown that AR(1) model with Weibull innovations provides best solutions for annual series and AR(1) model with generalized logistic innovations provides best solution for monthly as compared with the results of artificial neural network models.

In this study, inventory&ndash / distribution system of a company operating in Fast Moving Consumer Goods (FMCG) industry is analyzed. The system is a multi&ndash / item, two-echelon, divergent inventory&ndash / distribution system with transportation constraints. The warehouses in the system are nonidentical and all of the warehouses are allowed to hold stock. The goal is to achive target customer service levels. Throughout the system, inventory is controlled by echelon stock periodic review (R, S) order-up-to level policy. The problem is the determination of inventory control parameters in the system and effective replenishment of the inventories of many items at regional warehouses under transportation constraints. An approach consisting of three modules operating in a hierarchy is developed to manage the system. The approach calculates the inventory control parameters of the items (order-up-to levels at the regional warehouses and stock allocation fractions) / determines the replenishment periods of the items with the objective of balancing the vehicle requirements among periods and performs the daily replenishment of inventories minimizing the maximum deviation from the inventory policy under transportation constraints. A heuristic approach is adapted from the literature for the inventory control parameter determination part of the approach / an IP model is formulated for the replenishment period scheduling part and a MIP model is constructed for the replenishment process. The proposed approach is simulated with retrospective data of the company and compared with the existing system in the company, in terms of the performance measures defined. Satisfactory results are obtained with the proposed system.

Recently, carbon dioxide injection into deep sea sediments has become one of the carbon dioxide mitigation methods since carbon dioxide hydrates are stable at the prevailing pressure and temperature conditions. The Black Sea, which is one of the major identified natural methane hydrate regions of the world, can be a good candidate for carbon dioxide storage in hydrate form. Injected carbon dioxide under the methane hydrate stability region will be in contact with methane hydrate which should be analyzed thoroughly in order to increase our understanding on the gaseous carbon dioxide and methane hydrate interaction. For the storage of huge amounts of CO2, geological structure must contain an impermeable barrier. In general such a barrier may consist of clay or salt. In this study, sealing efficiency of methane hydrate and long term fate of the CO2 disposal under the methane hydrate zone is investigated. In order to determine the interaction of CO2 and CH4 hydrate and the sealing efficiency of CH4 hydrate, experimental setup is prepared and various tests are performed including the CH4 hydrate formation in both bulk conditions and within sand particles, measurement of the permeability of unconsolidated sand particles that includes 30% and 50% methane hydrate saturations and injection of CO2 into the CH4 hydrate. Results of the experiments indicate that, presence of hydrate sharply decreases the permeability of the unconsolidated sand system and systems with hydrate saturations greater than 50% may act as an impermeable layer. Also, CO2-CH4 swap within the hydrate cages is observed at different experimental conditions. As a result of this study, it can be concluded that methane hydrate stability region in deep sea sediments would be a good alternative for the safe storage of CO2. Therefore, methane hydrate stability region in the Black Sea sediments can be considered for the disposal of CO2.

This thesis investigates problematic cases in AC substation grounding system design. Particularly, the grounding design for substations that are built on high resistivity soil is considered. Here, possible physical rectification schemes are introduced and compared for their effectiveness from safety and cost efficiency perspectives. For this comparison, the CYMGRD program (a finite element analysis tool for AC substation grounding) is used for detailed analysis of the various schemes. An additional computer program is developed to implement the formulations of the related AC substation standards (IEEE, IEE, and Turkish National Regulations). The output of this program is compared with the finite element analysis of the high-resistivity-soil rectification schemes to investigate the validity of the formulations in these standards.

Data analysis has become a very important area for both companies and researchers as a consequence of the technological developments in recent years. Companies are trying to increase their profit by analyzing the existing data about their customers and making decisions for the future according to the results of these analyses. Parallel to the need of companies, researchers are investigating different methodologies to analyze data more accurately with high performance. Recommender systems are one of the most popular and widespread data analysis tools. A recommender system applies knowledge discovery techniques to the existing data and makes personalized product recommendations during live customer interaction. However, the huge growth of customers and products especially on the internet, poses some challenges for recommender systems, producing high quality recommendations and performing millions of recommendations per second. In order to improve the performance of recommender systems, researchers have proposed many different methods. Singular Value Decomposition (SVD) technique based on dimension reduction is one of these methods which produces high quality recommendations, but has to undergo very expensive matrix calculations. In this thesis, we propose and experimentally validate some contributions to SVD technique which are based on the user and the item categorization. Besides, we adopt tags to classical 2D (User-Item) SVD technique and report the results of experiments. Results are promising to make more accurate and scalable recommender systems.

Angiography is an invasive procedure since contrast medium is injected into circulatory system of patients and the mostly preferred technique is X-ray angiography. For diagnosis, treatment planning, and risk assessment purposes, interventional radiologists utilize visual inspection to determine connectivity relations between vessels. This situation leads angiography to be more invasive, since it requires additional injection of contrast medium and X-ray dose. This thesis work presents a 3-D vascular connectivity tracking toolkit for automated extraction of vascular networks in 3-D medical images. The proposed method automatically extracts the vascular network connected to a user-defined point in a user-defined direction, and requires no further user interaction. The toolkit prevents additional injection of contrast agent and X-ray dose, saves time for the interventional radiologist. While the algorithm is applicable on all 3-D angiography images, performance of the method is observed on 3-D catheter angiography image of cerebrovascular structures. The algorithm iteratively tracks gravity centers of vascular branches in the user-defined direction, preserving connection to the user-defined point. Curvy branches are tracked even if they have discontinuous portions. Since this tracking method does not depend on lumen diameter and intensity differences, branches with stenoses and branches having large intensity difference can be successfully tracked. Skeletonization and junction detection methods are described, which are used to detect the sub branches, indirectly connected to the point. These methods are capable of handling bifurcations, trifurcations, and junctions having more branches. However, false junctions occurring due to superposition of vessels are not eliminated.

In this thesis, 3D animation of human facial expressions and lip motion and their synchronization with a Turkish Speech engine using JAVA programming language, JAVA3D API and Java Speech API, is analyzed. A three-dimensional animation model for simulating Turkish lip motion and facial expressions is developed. In addition to lip motion, synchronization with a Turkish speech engine is achieved. The output of the study is facial expressions and Turkish lip motion synchronized with Turkish speech, where the input is Turkish text in Java Speech Markup Language (JSML) format, also indicating expressions. Unlike many other languages, in Turkish, words are easily broken up into syllables. This property of Turkish Language lets us use a simple method to map letters to Turkish visual phonemes. In this method, totally 37 face models are used to represent the Turkish visual phonemes and these letters are mapped to 3D facial models considering the syllable structures. The animation is created using JAVA3D API. 3D facial models corresponding to different lip positions of the same person are morphed to each other to construct the animation. Moreover, simulations of human facial expressions of emotions are created within the animation. Expression weight parameter, which states the weight of the given expression, is introduced. The synchronization of lip motion with Turkish speech is achieved via CloudGarden&reg / &rsquo / s Java Speech API interface. As a final point a virtual Turkish speaker with facial expression of emotions is created for JAVA3D animation.

In order to use components that are developed for a domain, domain knowledge is required. If the default relations in a domain are offered by a framework, this can be a starting point for the application engineer as an important kind of domain knowledge. A generic design for creating and saving a domain is implemented in this thesis. This approach starts with creating a domain from components and relations among these components. The relations and components are saved once and used several times. In addition, this generic design helps for code generation by using components. A framework for this design is implemented and applied for GIS domain. A basic code generation approach is also implemented in this framework for demonstration purposes. This framework can be used by domain engineers in order to create a domain and by application engineers to develop custom applications. It has the ability to offer default relations and helps creating new relations between components. Parameters and sequence of function calls can be defined by using a GUI. All the relations including default and userdefined ones can be used for code generation. COSECASE, which offers a tool for component-oriented design is extended with domain operations such as creating domain, saving domain, loading domain, and generating domain code. As the starting point, domain analysis for GIS domain is completed to define the domain. Then the components that have been implemented for GIS domain and relations between these components are saved within the framework. Moreover, some basic applications are generated by using this framework in the GIS domain. Also a sample domain is created to prove that our approach can be applied to any domain. The relations in this sample domain are saved in the framework and same basic applications are generated.